Since enabling "arm" kernel sub-architecture introduced in linux-odroid-c2 3.14.79-25 breaks HW-accelerated decoding in Kodi - I propose to make a separate kernel. In this build changes introduced in linux-odroid-c2 3.14.79-25 and 3.14.79-26 should be reverted.
Also I admit that fixing aml-libs-c2 compatibility with upstream linux 3.14 would be a better solution, or even - "the solution". But on the other hand - the proposed kernel build would be a good temporary solution for new owners of ODROID-C2 who just want Kodi to work.
You can find more details on the problem here: https://archlinuxarm.org/forum/viewtopic.php?f=15&t=11777#p56259.
EDIT: Please consider this irrelevant - see my next comment.